The levels repeating is actually intended. The first five levels are hardcoded as a tutorial of sorts, and then it starts giving you random ones. The original idea for the game was a random gauntlet against the clock (hence why it never ends) but we ran out of time before adding the timer. Sorry.
And yeah, I would have hoped that the board could have been a bit faster and tighter but apparently Godot's physics are wack.
- Epsilon